AUSTRALIAN scientists are hoping to cure leukaemia, asthma and rheumatoid arthritis after their breakthrough discovery of how to stop killer blood cells growing.

The team has unlocked the secrets behind the protein which controls the way the blood cancer cells spread when it is damaged - and have found a way to stop its deadly process.

Work is now starting to design a drug to prevent the damaged proteins operating, effectively stopping the cancer as well as asthma and inflammatory diseases such as rheumatoid arthritis.

After spending a decade uncovering the structure of the receptor protein, which sits on the surface of white blood cells, lead researcher Professor Michael Parker, of Melbourne's St Vincent's Institute, said scientists could now build a drug to attach itself to the protein and stop it sending messages into the cells telling them to multiply unchecked.

"If we can stop the signal for the proliferation of uncontrolled growth of the cells then we can stop the leukaemia in its tracks," he said.

Working with molecular biologists at Adelaide's Hanson Institute, the Melbourne scientists used X-ray and synchrotron imaging to build an image of the structure of the protein for the first time, hoping to find a way to block its process.

The GM-CSF hormone - which controls the production of blood cells in the body - works by attaching itself to the receptor proteins, which then send a message into white blood cells telling them to multiply.

When damaged, the protein's messages cause an over-production of cells or cells which persist too long, resulting in diseases such as leukaemia as well as some inflammatory conditions.

The major breakthrough came when the researchers realised the proteins linked together to form networks on the surface of white blood cells after being activated by the hormone, and that by stopping the networks forming they could also stop the growth.

Liam Heudebourck, who was diagnosed with asthma four years ago, was yesterday hopeful about the discovery.

The Camden seven-year-old was admitted to hospital in March after suffering a major attack.

"If scientists found a cure or something that could help not to have his puffer every day, that would be great," his mother, Belinda English said.

While the drug development phase has only just begun, Professor Parker said it would be easier to target a protein on the surface of the cell rather than trying to come up with a molecule to break its way into the center of the cell.